Packaging process



June 8 1965 J. w. FEI-:NEY ETAL 3,187,480

PACKAGING PROCESS Filed Feb. 26, 1963 5. mw F JOSEPH W. FEENEY PAUL L. POJAWIS JAMES E. ALLENBAUG A R H JR. JoHN wMgnr/q Td.

ATTORNEY United States Patent C) 3,187,430 PACKAGENG PRCESS- Joseph W. Feeuey, Pilresvilie, Paul L Poiawis, Eaitirnore, James E. Allenhaugh, l'r., Towson, and John W.. McNair, Jr., Baltimore, Md., assignors to international Paper Company, New York, NX., a corporation of New York I Filed Feb. 26, 1963, Ser. No. 261,053 13 Ciairns. (Cl. 5ft- 29) This invention relates to packaging with paperboard in the form of folding cartions, carton lids, folders, trays, cards, and the like. More particularly, it relates to the y packaging of products having a grease content or being moisture-sensitive to a substantial degree.

Products having a relatively high grease content or being subject to moisture loss or gain, particularly shelftype foodstuff products such as cake and pie crust mixes, breakfast cereals, and the like, are now'commonly marketed in waxed glassine or plastic bags or liners inserted into a paperboard container upon which advertising and instructive information is printed. The waxed glassine or, for example, polyethlyene bags are filled, sealed orV crimped, and introduced into the container by the packager. In this type of packaging, the waxed glassine or polyethylene bays provide the barrier which keeps the grease of the product in (where it cannot provide a path for the spoilage or contamination of the product or the containers) or the moisture of the atmosphere or product out or in, respectively, and the containers provide protection against grosser injury to the product resulting from either normal or improper handling.

It is known that the bag-in-the-box variety of packaging, especially for foodstuffs, is not entirely satisfactory. The bags are difficult to fill, seal, and insert into the containers and the consumer has difficulty both in opening and re-closing this type of package, particularly where inadequacy in the re-closing can adversely affect the life of the product.

lt is also known that new advances in the art of laminating or otherwise bringing together paperboard and protective agents or barrier coatings such as parafn waxes, microcrystalline waxes, waxes blended with polymers, vinyl co-polymer blended waxes, polyvinylidene chloride, and polyolefins, have resulted in improved grease and moisture barrier characteristics for the paperboard. In'consequence, in some instances, products can be packaged safely and attractively in containers made of the augmented paperboard and without recourse to waxed glassine or plastic bags. See, for instance, U.S. Pat. Nos. 2,999,758 and 3,015,596.

Heretofore, however, there does not appear to have been developed a paperboard-based packaging material, design, or method which results in a single unit folding carton or the like having substantially equal utility for grease-bearing or exuding products and water-absorbing or water-emitting products and creating no additional problems. It has been proposed to place a barrier coating of plastic or the like on the inner wall of a paperboard folding carton to abut a greasy product and to contain the grease, but this leaves the Vouter wall of the carton and the edges thereof without the requisite resistance to grease penetration, moisture vapor transfer, or water absorption. It has been proposed to place a barrier coating on the outer wall of a paperboard folding carton for a water-absorbent product and to exclude moisture or water, but this leaves the inner wall of the carton and the edges thereof susceptible to attack by any fats or greases normally in the product and leads to dithculties in achieving and maintain-ing attractive printing or decoration of the outer wall. lt has been proposed to Patented' une 3V i965 lCev place barrier coatings on both the inner and outer walls of paperboard folding cartons, but this tends to diminish or obviate the economic advantage sought by the initial Y resort to paperboard as the carton material.

Or, it results in a packaging material inferior in performance to the bag-in-the-box combination.

Some of the objects of the present invention are to secure a paperboard-based packaging material, design and method productive of a single unit folding carton or its equivalent having a superior grease, moisture or water, and gas transmission barrier property and other characteristics such as printability, product davor retentivity, sifting loss resistance, external odor product contamination resistance, and insect and fungal product attack resistance. Other objects will become evident te those skilled in the art from the following disclosure.

Broadly, the present invention encompasses a procesa made up of steps of (a) barrier coating at least one sur-- face of a paperboard web ofY sheet; (b) die cutting flat,

folding carton blanks having free edges from the barrier coated web or sheet; (c) tightly compressing a stack of plurality of the fiat fold-ing car-ton blanks; (d) submerging the compressed stack in a bath of free edge sealing material for pre-determined dwell time; (e) removing the compressed stack from the bath; (f) forming folding cartons, wherein a barrier coated paperboard web or sheet surface is disposed interiorly, from the at folding carton blanks; (g) filling the `formed folding cartons with a product characterized by at least one of the conditions selected from a group consisting of grease-bearing, moisture-sensitivity, and ygas sensitivity; and, (h) closing the illed cartons. Preferably, the paperboard web or sheet or, more generally, substrate is previously prepared -for printing, a-s by being `clay coated in accordance with conventional procedures, on that surface which is not to be barrier coated in accordance with the present invention or on top of one of the barrier coated surfaces. Also it is preferable, not to say most convenient, to accompanythe die cutting step with a blank scoring step. Again, it has been found preferable to have the bath hot and agitated during the stack submersion, so as to promote the penetration and the sealing of the free edgesby the sealing material. A sealed free edge drying period is also `desirable'. Then too, the step of printing Vthe blanks on their non-barrier coated surfaces with indicia of advertising and instruction before the cartons are formed and the use ofV adhesives or heat sealing to assist in the carton closing is preferred.

Among the grease, moisture, yand gas barrier coatings found useful in the practice of the present invention are, and these are cited from a broad grouping only for example, low, medium, and high density polyethylene, polyvinylidene chloride, aluminum foil, grease-proof paper, glassine, alone or in combination with each other or laminating-promoting agents. These materials were laid down in thicknesses of from about 0.0001" to 0.0015 on paperboards having thicknesses of from about 0.013" to 0.24" and made commercially available by International Y Paper Company under the trademarks Mosscoatj Snoorite, lPBf and IPXl These boards are all clay coated'for printing purposes and made fromv bleached sulfate pulp -or' other mixed virgin pulps, but they vary in density.

Among the folding carton blank designs having particular utility in accordance with the present invention are the three depicted in the plan views of attached FIG- URES l, 3 and 5 and the isometric views of the cartons [formed therefrom in FIGURES 2, 4, and 6.- FIGURE l shows a blank scored vertically, horizontally, and diagonally which yields the .web-cornered, especially sift-proof carton of FGURE 2 comprised-of side panels l0 and i2,

front panel 11, back panel 13, and glue panel 14, as well as top closure members or flaps 15, 16, 17, 18, and 19 and web corner portions 20, 21, 22, and 23 and comparable, but unnumbered bottom closure elements. FIG- URE 3 shows a blank scored vertically and horizontally which yields the carton of FIGURE 4 comprised of side panels 30 and 32, front panel 31, back panel 33, and glue panel 34, as Well as top closure members or flaps 35, 36, 37, and 38 and similar, unnumbered bottom closure parts. (It will be noted that flaps 35, 36, 37, and 38 are not merely bonded on their sides by slits separating them from one another, but that die cutting means have been utilized to produce V-cuts 39, 40, and 41 in flaps 35 and 37 and to free the edges of such sides from each other.) FIGURE shows a blank scored vertically and horizontally which yields the carton of FIGURE 6 comprised of side panels 40 and 42, front panel 41 (whereon printed instructive and advertising indicia 41a are shown), back panel 43, and glue panel 44, as well as top closure flaps, 45, 46, 47 and ears 46a and 46b and equivalent, unnumbered bottom closure portions. (It will be seen that the blank of FIGURE 5 is like that of FIGURE 3 insofar as it utilizes enlarged or V-cuts to free the edges of flaps 45 and 46 from those of ears 46a and 4611 and flaps 48).

To date, the blank and carton of FIGURES 5 and 6 have given the best results under this invention. However, all of the blanks have in common the structural feature of free edges, i.e., exterior edges nowhere impinging upon or impinged upon by other edges of the same blank.

The apparatus for submerging a stack of at folding carton blanks like those depicted in FIGURES 1 to 6 in the edge sealing bath need involve, in a bench model, nothing more than metal, expanded metal, or even plywood platens, preferably cut to conform along their peripheries with the outlines of the blanks they are to hold; mechanical, pneumatic, or hydraulic clamping means to hold the platens in place and tightly compress the stack so as to prevent seepage of the edge sealing material between the flat surfaces of the folding carton blanks: a tank for the edge sealing material; means such as a chain hoist to lower the stack into the bath and raise it out of the bath; and, preferably a bath heating unit and a bath agitation unit, e.g., a stirrer or an ultrasonic vibrator. Production models can, of course, be further rened.

At least two classes of edge sealing materials can be employed in achieving the results of this invention. One class includes those agents which are inert to and do not react with the individual cellulose fibers exposed along the free edges of the paperboard carton blanks and the neighboring fibers, but, rather, have the capability of filling the interstices or voids between such fibers. A hydrogenated castor oil such as Archer-Daniels-Midland Companys Hydrofoil Glycerides #200 or Baker Oil Companys Castorwax falls into this class. The other class includes those agents which react with the individual cellulose fibers contacted and an example of such an agent is the water-soluble uorochemical chromium complex otherwise described as the chromium (Cr III) complex of N-ethyl-N-heptadecyluoro-octane sulfonyl glycine and sold by the 3M Company under the designations FC-805 Paper Chemical and Scotchgard Iust how effective a combination of the foregoing process steps and substrates, barrier coatings, folding carton blank designs, and free edge sealing materials can be is both unexpected and surprising. For example, a barrier coated stock was produced by conventional 1aminating means which comprised 1b. opaque glassine/ 1.5 mil polyethylene/0.015 IPB paperboard. About 150 carton blanks conforming to FIG. 5 were cut from such stock and stacked. Then, the stack was compressed under about 20 lbs. per. sq. in. pressure between two platens and lowered into a bath of FC-SOS Paper Chemical. The temperature of the bath was about F. and it was continuously agitated during the submersion of the stock in the bath. The submersion lasted approximately 10 seconds. The stack was then withdrawn from the bath and the free edges of the blanks were permitted to dry for 24 hours at room temperature and 44% relative humidity. Next, cartons were formed from some of the blanks and the cartons were lled with an apple raisin cake mix, marketed by a well-known manufacturer under the Duncan Hines imprint, into which a red dye had been introduced. Thereafter, the filled cartons were placed in an oven, held at a temperature of F, for 3.25 weeks and, thereby, subjected to a shelf-life of about 13 weeks. At the end of the oven treatment, no incursion of the red dye along the edges of the cartons or on their surfaces was visible to the naked eye, though, by way of contrast, varying, but serious, degrees of such incursions-denoting edge-wicking of the grease content of the cake mix by the paperboard of the cartons-was noted in sample cartons similar in design and manufacture except for the exclusion of the barrier coating or the edge sealing or both. Additional tests, the same or closely similar in all particulars, except that Castorwax was used in place of the IFC-805 Paper Chemical and the immersion therein took place in a bath held at about 320 F. with a dwell time of about 3.5 minutes, have been conducted with generally comparable results.

There is every reason to believe that the foregoing presents or suggests solutions to problems arising in other areas of the packaging field. The packaging `of fiuids such as milk and dairy products derived therefrom, frozen goods such as meats, soaps and detergents, and lubricated metal parts can be advanced by one or more of the several aspects of this invention.

What is claimed is:

1. A process comprising the steps of (a) disposing at least one barrier coated selected from the group consisting of paraffin waxes, microcrystalline waxes, waxes blended with polymers, vinyl co-polymer blended waxes, polyvinylidene chloride, aluminum foil, glassine, grease-proof paper, and polyolens on at least one surface of a paperboard substrate;

(b) die cutting flat folding carton blanks having free edges from the barrier coated paperboard substrate;

(c) tightly compressing a stack of a plurality of the flat folding carton blanks between platens so as to have only the free edges exposed;

(d) submerging the compressed stack in a bath of free edge sealing material selected from the group consisting of water-soluble fluorochemical complexes and hydrogenated castor oils for a pre-determined dwell time;

(e) removing the compressed stack from the bath;

(f) forming cartons, wherein the barrier coated paperboard substrate surface is disposed interiorly, from the bathed flat folding carton blanks;

(g) filling the formed cartons with a product characterized by at least one of the conditions selected from the group consisting of grease-bearing, moisture-sensitivity, and gas sensitivity; and

(h) closing the lled cartons.

2. The process of claim 1 wherein the other surface of the paperboard substrate is previously prepared for printing.

3. The process of claim 1 wherein the other surface 0f the paperboard substrate is previously clay coated.

4. The process of claim `1 wherein the die cutting step is simultaneously accompanied by a carton blank scoring step.

5. The process of claim 1 wherein the compressing step is conducted with sufficient pressure to prevent seepage of the free edge sealing material between individual at carton blanks in the stack.

6. The process of claim 1 wherein the submerging step is conducted in a hot bath of the free edge sealing material.

7. The process of claim -1 wherein lthe submerging step is conducted in an agitated bath of the free edge sealing material.

8. The process of claim .-1 wherein the submerging step is conducted in an ultrasonically agitated bath of the free edge sealing material.

9. The process of claim 1 Iwherein the forming ystep is preceded by a step of printed indicia of instruction and advertising on the bathed at carton blanks.

10. The process of claim 1 wherein the free edge sealing material is the chromium (Cr III) complex of N-ethyl- N-he-ptadecyluoro-octane sulfonyl glycine.

1:1. The process of claim 1 wherein the ree edge sealing material is a hydrogenated castor oil.

1.2. The process of claim 1 lwherein the Isubmerging step is conducted in an agitated aqueous bath of the chromium (Cr III) complex of N-ethyl-N-heptadecylfiuoro-octane sulfonyl glycine having a temperature of about 75 F. for about 10 seconds.

413.v The process of `claim 1 'wherein the submerging step is conducted in an agitated bath of hydrogenated castor oil having a temperature of about 320 F. for about 3.5 minutes.

References Cited by the Examiner UNITED STATESA PATENTS 2,019,242 10/ 35 Aument 93--36 2,555,315 6/51 Carroll 93-36 2,796,007 6/ 57 Bergstein 93-36 2,984,161 5/6l Cook et al 93-36 v3,013,709 12/61 Mason 2293.1

3,055,152 9/62 Williams 53-29 v A. LOUIS MONACELL, Primary Examiner.

RAYMOND N. JONES, Examiner. 

1. A PROCESS COMPRISING THE STEPS OF (A) DISPOSING AT LEAST ONE BARRIER COATED SELECTED FROM THE GROUP CONSISTING OF PARAFFIN WAXES, MICROCRYSTALLINE WAXES, WAXES BLENDED WITH POLYMERS, VINYL CO-POLYMER BLENDED WAXES, POLYVINYLIDENE CHLORIDE, ALUMINUM FOIL, GLASSINE, GREASE-PROOF PAPER, AND POLYOLEFINS ON AT LEAST ONE SURFACE OF A PAPERBOARD SUBSTRATE; (D) DIE CUTTING FLAT FOLDING CARTON BLANKS HAVING FREE EDGES FROM THE BARRIER COATED PAPERBOARD SUBSTRATE; (C) TIGHTLY COMPRESSING A STACK OF A PLURALITY OF THE FLAT FOLDING CARBON BLANKS PLATENS SO AS TO HAVE ONLY THE FREE EDGES EXPOSED; (D) SUBMERGING THE COMPRESSED STACK IN A BATH OF FREE EDGE SEALING MATERIAL SELECTED FROM THE GROUP CONSISTING OF WATER-SOLUBLE FLUOROCHEMICAL COMPLEXES AND HYDROGENATED CASTOR OIL FOR A PRE-DETERMINED DWELL TIME; (E) REMOVING THE COMPRESSED STACK FROM THE BATH; (F) FORMING CARTONS, WHEREIN THE BARRIER COATED PAPERBOARD SUBSTRATE SURFACE IS DISPOSED INTERIORLY, FROM THE BATHED FLAT FOLDING CARTON BLANKS; (G) FILLING THE FORMED CARTONS WITH A PRODUCT CHARACTERIZED BY AT LEAST ONE OF THE CONDITIONS SELECTED FROM THE GROUP CONSISTING OF GREASE-BEARING, MOISTURE-SENSITIVITY, AND GAS SENSITIVITY; AND (H) CLOSING THE FILLED CARTONS. 